3 +  5 ==>Error: wrong spaces bet. tokens.
70 / 12 = 5.83333333333
80 - 20 = 60
700 / 100 = 7.0
10 * 15 = 150
 82 -- 5 ==>Error: Illegal operator.
 * 89 92 ==>Error: Illegal operator.
 a + b ==>Error: Illegal operand(s).
** 12 % 15 ==>Error: wrong spaces bet. tokens.
6+5 ==>Error: wrong spaces bet. tokens.
------- ==>Error: wrong spaces bet. tokens.
9 / 0 ==>Error: Zero division not allowed.
6 - 10 = -4
 ==>Error: wrong spaces bet. tokens.
7.8 * 2.3 = 17.94
**************** ==>Error: wrong spaces bet. tokens.
18  + 17 ==>Error: wrong spaces bet. tokens.
-7 + -9 = -16
-10 * -12 = 120
-13.45 / 7.62 = -1.76509186352
250.4 - 17.9 = 232.5
5 / 0 ==>Error: Zero division not allowed.